UBS is testing blockchain technology to enhance digital gold investments for retail clients, utilizing ZKsync Validium to improve scalability, privacy, and interoperability. The bank's Key4 Gold product, initially on a permissioned blockchain, aims for global expansion while ZKsync targets processing 10,000 transactions per second by 2025 with minimal fees. Privacy-preserving technologies are seen as crucial for driving institutional adoption of blockchain, potentially unlocking significant capital in the crypto space.